Metallic packing for pistons



(No Model.)

W. H. LANG.

METALLIC PACKING FOR PISTONS.

Patented Sept. 28, 1886.

Zzven to)? M; M cfl m UNITED STATES PATENT @rrrcn.

WVILLIAM H. LANG, OF BURLINGTON, VERMONT.

METALLIC PACKING FOR PISTONS.

SPECIFICATION forming part of Letters Patent No. 350,004, dated September 28, 1886.

Application filed June 25, 1886. Serial No. 206,235.

To aZZ whom it may concern:

Be it known that I, \VILLLIM H. LANG, of Burlington, in the county of Ohittenden and State of Vermont, have invented a new and useful Improvement in Metallic Packings for Pistons; and I do hereby declare that the following isa full and accurate description of the same.

This invention relates to that class of metal- 110 piston-packings wherein the packingring is severed transversely, and therefore composed of several segments; and it consists in a segment-ring composed of two or more rings fitted together and cut at different points to produce a lap-joint, as will be more fully explained hereinafter.

Figure l is aperspective view of my piston and packing. Fig. 2 is an axial section of the same. axis. Fig. 4 is a perspective view of the spring-case. Fig. 5 is a perspective view of the spring. Fig. 6 is a transverse section of the packing-ring.

I am aware that the segment-rings for pistonpackings have heretofore been made with lapped joints made by scarfing and lapping the adjoining ends of said segments, and also by slotting and fitting therein tongue-pieces. These fittings are mostly performed by hand, and it is practically impossible in that way to produce desirable accuracy for fit.

I am also aware that piston-packings have heretofore been made with several rings fitted together, severed at opposite points, and retained in position loosely by dowel-pins; but this differs from mine because it is not a single ring constructed in a composite way with accurately-fitted parts rigidly riveted together, but does consist of several parts necessarily loosely connected, so as to be capable of expansion. By my invention all parts of the work are performed by machine-tools, and it is easy to secure the greatest accuracy at all points.

Without proposing to limit myself to the exact details shown, I will now describe the method of construction which I prefer.

My packing-ring is composed of a central section or core, a, i-shaped in cross-section, the horizontal web or flange being equal to the width of the packing-seat s in the pistonhead A, and the vertical web or flange exceeds the depth of said seat. The ring a is Fig. 3 is a section transverse to the (No model.)

turned and completed on the turninglathe. Two other rings, Z) c,'are then prepared in the same way and accurately fitted to the angle on either side of the vertical flange a. Holes are then drilled for rivets to secure the three rings together, and they are then put on the lathe and all finished together, thus securing coincidence of surface. The rings a b 0 are then separated and severed transversely at several points-say six or more; but the ring a is cut at points not coincident with the points of severance for the rings 1) c. Rivets are then put in and the three parts a b c of each segment firmly secured together. In this way, as will be apparent, the segments have each at one end a L-shaped tongue and at the other a corresponding slot undercut transversely to fit the corresponding tongue of the adjoining segment, and the adjoining surfaces are all fitted to each other with the greatest facility and ac curacy by machinery and without hand-fitting. This is of great consequence, because the greatest difficulty in hand-fitting is in fitting angular surfaces to each other.

YVhile the machine-work insures greater accuracy, it also greatly reduces the cost.

All packings of this class are provided with under springs to render the packing elastic and self-expansible, so that if the cylinder wears slightly out of true the packing-ring will follow the inequalities and preserve a tight joint. My under springs, f, are placed in cells 9, bored radially in the piston head; but I do not permit them to bear directly against the packing-ring, nor chafe against the side of the cell 9. I therefore provide for each spring a housing, h, fitted to slide in said cell and bored out interiorly to receive the spring f. At its outer end said housing is provided with an axial stud, 2', adapted to enter and be seated in a shallow cell, k, in the under side of the segment a near to its joint with the adjacent segment. The ring is therefore retained uniformly in place on the piston-head, and being restrained from rotation it will wear in common with that portion of the cylinder traversed by it, and will therefore maintain uniformly a tight j oint. In a segmental ring destitute of means for restraining each segment individually, the several segments, instead of expanding and contracting uniformly, will be caused by unequal friction in the joints to move toward each other, finally leaving all the joint opening at one place and a correspondingly undesirable opportunity for the escape of steam. In horizontal engines this 5 bunching of the segments will be aided by the influence ot'gravity, and the openingwill occur on the uppersideof the piston. Ifthe springs f were connected directly to the segments, they would also be pressed against the sides of their IC cells, with consequent chafing and destruction. This is entirely obviated by the housing h.

Having described my invention, I claim- 1. A segmental packingring wherein each i 5 segment has at one end the -shaped tongue herein shown and described, and at the other end a corresponding vslot and undercut transversely to fit the corresponding tongue of the adjoining segment, substantially as shown.

2. A segmental packing-ring composed of 20 the concentric parts ab 0, having the cross-section, substantially as shown, the rings 7) 0 cut transversely at points not coincident. with the point where ring a is cut, and the several parts riveted together to constitute solid segments, as set forth. Y

3. A segmental packing-ring combined with housings h, which enter cells 9 in the pistonhead and cells 70 in said ring, and the springs f within said housings, as set forth.

WILLIAM H. LANG.

Witnesses:

HAMILTON S. PEcK, HERMAN K. WEAVER. 

